One of my HD-DVR's has started having video noise when viewing a program. I thought it might be my HDMI cable or a poor connection, so I unplugged and reseated the cable on each end. I was going to swap out the cable, but then I noticed that there is no noise on the menus or banners, just on the programming itself. I've reset the DVR but it's still there. Does anyone have any suggestions or is it time for a replacement?